<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>

        function changeCode() {
            let imgObj = document.getElementById("codeImg");
            imgObj.src = "/checkCode?"+Math.random();
        }
    </script>
</head>
<body>
    验证码：<img src="/checkCode" id="codeImg"/>
    <a href="javascript:changeCode()">看不清，换一张</a><br>
    请输入验证码：<input type="text" name="code">


</body>
</html>